Traverse control



H. E. BALSIGER TRAVERSE CONTROL original Filed April 21, 1937 Oct. 20, 1942.

Patented Oct. 20, 1942 UNITED starts cargar ortica Harold E. Bralsiger, Waynesboro, Pa., assigner to l Landis Tool Company, Waynesboro, Pa. Original application April 21, 1,9317, ScriaLNo. 138,245, lbW Patint N0. 2,249,343, dated July 15, 1941. Dividd 'and this IJ'pli'C'atiOIl Nvlbei' 3, 1939, Serial N0. 302,761

7 Claims.

.valve when pressure on the 'traverse mechanism is released.

In the drawing, Figure 1 is a front elevation or" a metal working vmachine cut away to show the relation between the various parts.

Referring to the drawing, Figure 1, numeral indicates the b'ed of a metal working machine, and I a 'work carriage Y'sli/dably mounted thereon. Said carriage may be actuated manually by any of the well known manual traverse mechanisms. Power means for effecting Aa reciprocating movement of said work support include two cylinders |1El and |11 in which are mounted pistons |12 and |13 respectively. Piston ends |14 and |15 are connected to carriage by means of brackets |16 and |11 respectively. Reciprocation of said carriage is effected by a reversing mechanism consisting of a lever |92 `actuated by movement of the carriage, a pilot valve V45 shifted by said lever for directing fluid under pressure to shift a reversing valve 55. This reversing mechanism is ldescribed in detail in my application Serial No. 138,245 of which this is a division.

A lever S1 acts as a start and stop control for the traverse mechanism as well as for a work drive motor, not shown. A cam surface 40 on said lever actuates a work drive motor control switch 4|. Said lever is connected by means of link 42 to start and stop valve '43 of the traverse control mechanism. Said mechanism consists of a housing 44 inwhich is mounted a relief valve 59, 'a start and stop valve 43, a reversing valve 55, and a bypass valve 58. i The bore containing said relief valve "extends the entire Width of the housing '44,"tl1'eiend'of said bore is closed by a cap 5| inserted therein. A passage 53 connects valve 5D with start and stop valve 43, A passage 54 connects valve 43 with reversing valve 55. An extension 51 of passage 54 serves to direct uid to the left end of bypass valve 53. A spring 55 mounted in a hollow end portion of said valve 5S urges said valve to the left. Two ports 59 and G' are connected by passages thru the front part of the housing 44 vin which are mounted 'a pair of check valves Vtl and 62. Said ports are also connected to the opposite sides o'f a throttle valve 1|. Each of said check valves is inserted in a recess 59 and 65 'which in turn is connected to 'port 59 or 'Sil as shown. Both of said check valves 4are supplied with fluid under pressure 'thru passage 54a. Adjusting screws Si! and 9| deterinine the maximum opening of said check valves. An exhaust 'passage 63 connects the right hand end of all the valves. A spring serves to hold the bypass valve 53 in an extreme left hand .position in the absence of fluid under pressure at'that point. Reversing valve 55 directs fluid from the passage 54 alternately through passages |50 and |51 to 'opposite ends of a traverse motor.

The start and stop valve 43 and lever 31 are shown in central position. In the left hand position of'said lever the switch 4| is open rendering the headstock motor inoperative. VVh'en Vsaid lever is in the left hand position, valve 43 is in the extreme right hand position and thus cuts oi the supply di uid under pressure from 'passage Passage 5'4 isconected to exhaust passage 63. In the central position of lever 31 switch 4| is closed and the he'adstock motor started. In the right hand position of lever 31 the switch is still held in closed position and valve 431s moved far enough to the left to open passage 53 completely and to close .passage y63. Fluid under pressure is then directed through passages 5'4 and 54a to the traverse motor.

The relief valve 5 consists of a movable piston element having a hollow portion in which is mounted a spring 15. Said spring urges said piston to the left or closed position against a seat formed by the inner end vof cap 5i. The otherend of said spring is seated in a cup shaped member 16 having a yhole 11 therein to prevent fluid from becoming locked between said cup and the end cap 18. Other holes (not shown) in the periphery of said member 16 permit passage therethru of uid in exhaust passage 63. adjusting screw 19 is threaded in said cap and bears against said cup 16 for varying the setting of the valve. In 4response 'to an excess of fluid, relief valve 50 will be shifted enough to permit such excess to enter port from passage 8| in said valve. From port 8U duid may pass through passage 82 to exhaust passage 63. A valve 91 in the exhaust passage 63 is held against its seat by means of a spring 99. The purpose of this valve is to keep a slight back pressure in the exhaust system and at the same time to prevent drainage of fluid from the control valve.

Operation To start the machine the operator must open throttle valve 'II to permit fluid to pass therethru between the cylinders I'Ill and I1I, then he must shift valve 43 to the left by means of lever 3l. Cam 48 on the lower end of said lever actuates limit switch 4I to start a Work drive motor, not shown.

Fluid under pressure is supplied to the valve housing 44 from pump |80 through line I8I from which it passes through relief valve 58 and passage 53 to valve 43. Upon shifting valve 43 to the left fluid from passage 53 is directed to passage 54 through which it passes to passage 51 and then to the left end of bypass valve 58 shifting said valve to the right thus preventing passage of fluid therethru between cylinders |10 and Ill and causing fluid to pass through throttle valve 1l. Said valve 'II determines ythe traverse speed of the carriage I I. Fluid under pressure passes from passage 54 through passage 54a and then through either or both of the check valves 6I and 62 and ports 59 and 50 to insure that the rod ends of the two cylinders |70 and III and a connecting line are kept full of oil and free of air. When pump |80 is stopped, check Valves 5I and 62 prevent fluid from draining out of the cylinders. lever 31 and valve 43 are shifted to stop position the passage 53 is connected to exhaust line 63 and the fluid is returned to the reservoir. Pressure is thus removed from the left end of valve 58 and said valve is shifted to the left by spring 65.

In this position of valve 58 lines 'I2 and 'I3 leading to the inner ends of cylinders Il@ and III respectively, bypass throttle valve 'Il and thus permit a free flow of fluid from one cylinder to the other while the carriage II is traversed manually.

I claim:

1. A grinding machine having a reciprocable carriage, a hydraulic motor for driving said carriage comprising a pair of cylinders, a start and stop valve, a piston in each cylinder, connections between said motor and said carriage, a control valve for directing fluid under pressure alternately to one end of each of said cylinders, a line connecting the opposite ends of said cylinders, a throttle valve in said line for controlling the speed of said carriage, a fluid operated bypass valve for permitting an unobstructed passage of fluid around said throttle valve, and means for opening said bypass valve when the supply of fluid to said traverse motor is cut off by said start and stop valve.

2. A grinding machine having a reciprocable carriage, a hydraulic motor for driving said carriage comprising a pair of cylinders, a start and stop valve, a piston in each cylinder, connections between said motor and said carriage, a control valve for directing fluid under pressure alternately to one end of each of said cylinders, a line connecting the opposite ends of said cylinders, a throttle Valve in said line for controlling the speed of said carriage, a fluid operated bypass valve for permitting an unobstructed passage of When fluid around said throttle valve, means for opening said bypass valve when the supply of fluid to said traverse motor is cut off, and means for directing fluid under pressure to operate said bypass valve when fluid is also directed to said motor by said start and stop valve.

3. In a grinding machine, a bed, a carriage slidably mounted thereon, means for causing a reciprocating movement of said carriage comprising a hydraulic motor, a reversing valve for said motor, a line connecting opposite sides of said motor, a throttle valve in said line for controlling the speed thereof, a valve for bypassing fluid around said throttle valve, a start and stop valve for controlling the flow of fluid to said reversing valve, and means for operating said bypass Valve in response to fluid under pressure from said start and stop valve.

4. In a grinding machine, a movable carriage, manual means for effecting a traversing movement of said carriage, power means for effecting a traversing movement of said carriage comprising a fluid motor, a supply of fluid under pressure, a start and stop valve for controlling said supply, a passage connecting opposite sides of said motor, a throttle valve in said passage for controlling the speed of said motor, a pressure operated valve for bypassing said throttle valve, and pressure responsive means for actuating same, connections from said start and stop valve to said motor and vsaid pressure responsive means for closing said bypass valve during power traverse to cause fluid to pass thru said throttle Valve.

5. In a grinding machine, a movable carriage, manual means for effecting a traversing movement of said carriage, power means for effecting a traversing movement of said carriage comprising a fluid motor, a supply of fluid under pressure, a start and stop valve for controlling said supply, a valve for adjusting the rate of movement of said carriage, a pressure operated bypass valve, fluid connections from said start and stop valve to said motor and said bypass valve for actuating said bypass valve to connect opposite sides of said motor and for rendering said rate adjusting valve inoperative when the supply of fluid to said motor is cut off.

6. In a metal working machine, a movable member, a hydraulic system including a motor for effecting movement of said member, a valve for controlling the rate of movement of said motor at any point in its travel, a start and stop valve and a pressure operated bypass valve for rendering said rate control valve operative or inoperative in response to starting or stopping the flow of fluid under pressure from said start and stop valve.

7. In a metal working machine, a movable member, a hydraulic system including a motor for effecting movement of said member, a valve for controlling the rate of movement of said motor, a start and stop valve and a pressure operated bypass valve for rendering said rate control valve operative or inoperative at any point in the travel of said motor in response to starting or stopping the flow of liquid under pressure from said start and stop valve.

HAROLD E. BALSIGER. 

